It's a skill of an Australian aborigine. The picture above (as far as I can tell) is of a replica made of a skull found in 1905 and known to belong to a 50 year old man from the Bindaboo tribe.
As far as I am aware it is an accurate replica not intended to be racist. I am far less certain of the poster's intentions, but I am going to give them the benefit of the doubt, this is probably the best looking image that comes up when you search "Australian skull".
With training, sufficient data, and experience one can determine the likely, or several most likely ancestries of a person from a skeleton. A forensic anthropologist who is credible will never say definitively from just a skeleton, but will say “most likely” or “appears to be.” Sex is the easiest thing to tell from a skeleton, age is next difficult and usually “adult” “adolescent” or “child” with maybe a best approximation of age is the best you’ll get. “Race” is much harder because while certain traits tend to be more prominent in certain groups- not all people fit the “average” for their group. There is overlap which can leave ambiguity, and even more so- as we move forward through human history, advances in technology and migration lead to increased mixing of distinct backgrounds and so more and more people have genetics that can lead to skeletons with traits from various groups.
Bit rude tbh
As far as I am aware it is an accurate replica not intended to be racist. I am far less certain of the poster's intentions, but I am going to give them the benefit of the doubt, this is probably the best looking image that comes up when you search "Australian skull".